Merge pull request #4160 from simplymanas/master

Merged by aniket965

Java/DataStructure/Arrays/HasDuplicate.java

@@ -0,0 +1,40 @@
+/*
+Given an array of integers, find if the array contains any duplicates.
+
+Your function should return true if any value appears at least twice in the array,
+ and it should return false if every element is distinct.
+ */
+
+
+
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Set;
+
+public class HasDuplicate {
+    public static boolean containsDuplicate(int[] nums) {
+        Set<Integer> set = new HashSet<>();
+
+        for(int i=0;i<nums.length;i++){
+            if (set.contains(nums[i])) { return true; }
+            else { set.add(nums[i]); }
+        }
+        return false;
+    }
+
+    public static void main(String[] args) {
+        int[] input = {1, 2, 3, 4,4, 5};
+        System.out.println(Arrays.toString(input));
+        System.out.println(containsDuplicate(input));
+    }
+}
+
+/*
+alternate solution
+public boolean containsDuplicate(int[] nums) {
+        HashSet<Integer> set = new HashSet();
+        for(int i = 0;i < nums.length;i++)
+           set.add(nums[i]);
+        return set.size() != nums.length;
+    }
+ */